CVE-2026-8401

9.8 CRITICAL 0.3% exploit odds Fix listed Other Browser & mail

What it is

Sandbox escape in the Profile Backup component. This vulnerability was fixed in Firefox 150.0.3, Firefox ESR 115.36, Firefox ESR 140.11, and Thunderbird 140.11.

At a glance

Exploitability: Can be exploited over the network without logging in. High risk of data exposure, data tampering, service disruption.
Exploit odds: 0.3% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-05-12 15:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-10-26 18:10 UTC Last updatedMost recent change to the record

Details

Published: 2026-05-12 15:16 UTC
Last modified: 2026-10-26 18:10 UTC
Exploit probability: 0.3% · EPSS, next 30 days
Weakness: CWE-693
Record status: Modified

Affected

Mozilla Firefox < 150.0.3

Attack profile CVSS 3.1 · 9.8

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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Fix and advisories

https://www.mozilla.org/security/advisories/mfsa2026-45/

References

NVD record · CVE.org record